Treatment of motor fuels



Patented Oct. 29, 1940 UNITED, STATES PATENT... OFFICE 2,219,859TREATMENT or MOTOR FUELS James G. White, Kingsport, Tenn assignor toEastmanKodak Company, Rochester, N. Y., a corporation of New Jersey NoDrawing.

storage with loss in such valuable properties'as' light color, low gumcontent and antiknock value, the deterioration being due principally tooxidation and being accelerated by the photochemical action of light.Straight run gasolines, on the other hand, do not ordinarily have thesame undesirable tendency to deteriorate, although blended stockscontaining cracked gasoline 'and straight-run gasoline usually show theundesir- -able tendency to deteriorate. Similar fractions of hydrocarbondistillates produced by the distillation of hydrocarbonaceous materialsother than petroleum frequently also show a tendency to deteriorate uponstorage.

It 'has been found that such deterioration of hydrocarbon motor fuelscan be retarded to a greater or lesser degree by incorporating in themotor fuel certain phenols, aminophenols and/or phenylene' diamines. Themajority of such inhibitors are solid substances which are not highlysoluble in hydrocarbon motor fuels and at best dissolve but slowly inthe fuel. Accordingly, it is difllcult to obtain a uniform distributionof the inhibitors in the motor fuels without resorting to time-consumingmethods of, violent agitation of the motor fuel stock being treated.Furthermore, where huge quantities of gasolines are being stabilizedwith such inhibitors on a commercial scale, any methods involvingviolent. agitation are wholly impractical. v s

It is essential in large scale operations to be able to blend theinhibitors into the motor fuels in a manner which permits a rapiduniform distribution of the inhibitor throughout the motor fuel Anyuneven distribution of the inhibitors throughout the treated stock isclearly undesirable.

From the practical standpoint of handling motor fuels during thetreatment thereof with inhibitors, it is usually most desirable to feedthe inhibitors continuously or. intermittently into a flow of the fuel.However, the aforesaid solid inhibitors do not ordinarily rapidlydissolve and Application March 18, 1939, Serial No. 262,705

mobile solutions of the inhibitors which can be fed into the flow ofgasoline.

Among other solvents which have been proposed for this purpose is methylalcohol. Methyl alcohol is a good solvent for the aforesaid in- 5hibitors and does not have a seriously deleterious effect on theinhibiting potency of the inhibitors. While methyl alcohol is a goodsolvent for the inhibitors, itdoes not have an especially gooddispersive action on the inhibitors in the 10 gasoline and is not fullysatisfactory where water is encountered in the gasoline, such as isordinarily the case under actual storage conditions. The butyl alcoholsare not a particularly good solvent for the aforesaid inhibitors (e. g.the in- 15 hibitors tend to separate from solution at lowertemperatures) but have a betterdispersive action on the inhibitors thandoes methyl alcohol. However, again, the butyl alcohols are notfullysatisfactory where water is encountered in the gaso- 20 line.

Ithas been proposed to employ a combination of methyl alcohol and abutyl alcohol as a solvent. However, such a combination, while servingto combine the good solvent powers of the 25 methyl alcohol with thegood dispersive action of the butyl alcohols does not avoid thedifliculties encountered when dealing with wet gasolines. Furthermore,in order to, arrive at solution which. gives a low cold test (i. e. asolution which does 30 not lose mobility, and from which the inhibitorsdo not tend to separate at low temperatures), it is necessary to employamajor proportion of methyl alcohol in the combination, so that thedispersive action of the butyl alcohols isonly 35 utilizedto arelatively small extent. Isopropyl alcohol is a better solvent than thebutyls for the aforesaid inhibitors and has a good dispersive action onthe inhibitors in the gasoline. Furthermore; isopropyl alcohol soluotions are not troublesome when wet gasolines are encountered. However,isopropyl alcohol solutions will not stand low cold tests, i. e. attemperatures of about -40 F., the ispropyl alcohol solutions becometroublesomely viscous and there 45 is some -tendency for theinhibitorsto separate from solution.

'I have now found that unlike butyl alcohol. solutions, isopropylalcohol solutions can be made to withstand low cold tests by incorporation therein of, not a major proportion, buta relatively small amount ofmethyl alcohol, so that they dispersive action of the isopropyl alcoholon, the inhibitors is not greatly depleted. I have further found thatethyl alcohol can be em- 65 Methyl alcohol methyl or ethyl alcohols isemployed, and most 10 advantageously, a mixture comprising about 10 toabout 20% by volume of methyl alcohol and 'the remainder of isopropylalcohol is employed. Such solutions readily disperse inv hydrocarbonmotor fuels and'have good cold tests.

15 The following examples are offered to illustrate typical solutionswhich I employ in practicing my invention. These examples are notintended to limit my invention.

Ezamplef 20 e 1 Grams- Isopropyl alcohol 25 Methyl fl1cOhQ1 5N-monomethyl-p-aminophenol 25 Example II Grams lgopmpyl alnnhnl 25Methyl alcohol 5 N-monobenzyl-p amin'ophenol 25 Example III Gramslgopropyl alcohol -'25-' Methyl 'nlrnhnl 5 85 N-monobutyl-p-aminophenol25 Grams Isopropyl alohhnl 25 Ethyl alonhhl 5N-monbbutyl-p-aminophenoLl- ..s 25

' Example V V Grams- A mixture consisting of about 92% by weight ofN-(n-primary-butyD-p-aminophenol and about 8% by weight of N,N'- di(n-primary butyl) p phenylenedi m n 49.3 kopropyl alcohol"; I. 47.9 59Methyl alcohol 5.3

soon a solution, which contains about -1o%by volume of methyl alcoholand about 90% by vol- -ume of isopropyl alcohol, when cooled to 40 F.

did not crystallize. n the other hand the following prior art solutioncrystallized atabol t .5- F. Grams a moot. consisting or about 92%by onweight of N-(n-primarybutyl) -p-amino-.

phenol and about 8% by weight of' N,N- di (n primarybutyl) pphenylnediOrdinarily, I have found it advantageous-to make up the solutions ofinhibitors in my new solvents, employing about one part by weight of theinhibitor to one by'weisht'of the solvent.

70 Other ratios of solvent to inhibitor can be employed.

.-8ui1lcient of the solution of the inhibitor should be incorporated inthe gasoline to give a concentration of inhibitor in the gasoline which-will substantially retard deterioration of useful and economicalconcentration of inhibitor will, of course, vary from inhibitor toinhibitor and motor fuel to motor fuel. The most advantaseousconcentration 1' inhibitor is, of course, readily determined. y makingthe ordinary tests and-observatibns customarily em- 10 ployed in theart. a

As phenol inhibitors, which are. especially useful in conjunction withmynew solvent, hydroquinone, diamyl-hydroquinone and catechol may bementioned; As aminophenolic inhibitors, N-alkyl-p-aminophenols, 'e. g.N-methyl-, N- benzyl-, N-n-primarybutyl, N-isobutyl-, N-isoamyl-,N-n-primary myl, N-hexyl-, N-heptyl-, N-octyl-,-andN-cetyl-p-aminophenols, are especially useful in conjunction with my newsolvent.- As phenylenediamine inhibitors, N,N'-dialkyi-pphenylenediamines, e. g. N,N'-di-(n-pri-.

marybutyl) and ,N,N-diisoamyl-p-phenylenediamines, are especially usefulin conjunction with my new solvent. Mixtures of N'-alkyl-p-amino- 5phenols and N,N'-dialkyl-l='-phenylenediamines, particularly thosecontaining a majority of N-alkyl-p-aminophenols, are especially'usefuliri conjunction with my new solvents. Mixtures of o N-alkyl-paminophenols and. N,N'-dialkyl-pphenylenediamine are described forexample in J,

the copending application of Harold Von Bramer and Albert C. Ruggles,Serial No. 96.467, filed August 1'7, 1936 (now U. S. Patent No.2,163,640, dated June 2'7, 1939). Y What I claim asmy invention anddesire to be secured by Letters Patent of the United line comprising asolution of an inhibitor 08138.-

ble of inhibiting deterioration of cracked gasoline selected from thegroup consisting of phenols, aminophenols and phenylenediamines, thesolvent of said solution comprising not more than about 20 by volume ofan'alcohol selected from the group consisting of methyl and ethylalcohols and at-least about 80% by volume of iso-'- propyl alcohol.

3. A deterioration inhibitor for a cracked gasoiine comprising asolution of an inhibitor capa- 6o ble of inhibitingdeterioration ofcracked gasoline selected from the group consisting of phenol, aminophenol and 'phenylenediamine inhibi-' tors, the solvent of said solutioncomprisingnot more than about 20% by volume ofmethyl alcoholjand-atleast about by volume of isopropyl alcohol. l

4. A deterioration inhibitor for cracked gasoline comprising asolutionof a N-alkyl-p-aminophenol inhibitor the solvent of saidsolution '70 phenylenediamine inhibitor, the solvent of said solutioncomprising about 16 to 20% by volume of methyl alcohol and about 90 toabout 80% by volume or isopropyl alcohol.

6. A deterioration inhibitor for a cracked gasoline comprising asolution of a N-alkyl-p-amino-phenol capable of inhibiting.deterioration of cracked gasoline and'in which aminophenol the alkylgroup contains at least four carbon atoms,

proportion, based on the and a substantial amount of the aminophenol, ofa N,N'-dia1kylp-phenylenediamine in which each alkyl group contains atleast four carbon atoms, the solvent or said solution comprising about10 to 20% by volume of methyl alcohol and from about 90 to about 80% byvolume of isopropyl alcohol.

'7. A method for stabilizing cracked gasoline against deteriorationwhich comprises adding to the gasoline a solution of an inhibitorcapable of inhibiting deterioration'of hydrocarbon motor fuels andselected from the group. consisting of phenols, aminophenols andphenylenediamines, the solvent of said solution comprising not more thanabout 20% by volume of-an alco- 10 hol selected from the groupconsisting of methyl and ethyl alcohols, and at least 80% by volume ofisopropyl alcohol. 7

JAMES 6. WHITE.

